This invention is directed to an optical fiber to integrated optical chip coupler wherein either a single or a plurality of optical fibers are securely held in precisely controlled spacing in a metal structure so that the fiber ends can be exposed, polished and coupled to optical channels in an integrated optical chip.
Optical fiber cores are small in diameter and the ends must be accurately coupled to other fibers or devices. Inaccurate coupling causes substantial loss in signal. When there is a plurality of fibers, it is essential that these fibers be maintained in precise relationship to each other. Prior art devices use V-grooves etched in silicon. The fibers are placed in these grooves and are held in place by a flat piece of silicon secured thereover. The silicon cover plate and the fibers are held in place with respect to the V-grooves by means of epoxy adhesive. It must be noted that forces applied to the fiber cause local changes in the index of refraction. Such changes in index cause transmission loss in the fiber. Such local changes are called "microbending." The microbending loss in a fiber due to the use of epoxy adhesive can be 1 decibel or greater. Such losses are objectionable and should be avoided.